The one thing that dissapoints me with the 1DX is the buffer size and the number of RAW frames possible to store during a high burst.The 35 frames takes only 3seconds, 3 !!!!! to fill the buffer..

Anyway, there seem to be something strange going on, since shooting m-RAW mode actually decreases the number of possible burts shots to 26, while shooting s-RAW mode increases the number to 39. I understand it takes some computing time to resize the RAW, but this will also happen while downsizine to s-RAW. Hence it is strange that the number of frames possible during m-RAW is "only" 26,which is a ridicilously small number which you will reach within 1.5sec !! Why could not Canon install a 3 x bigger buffer when the restof the camera is built for speed?? (shutter/cpu). The D4 can shoot up to 3 times more frames than the 1DX.

I have tested the 1DX with the fastest memory card currently available on the planet (Lexar 128G 1000x Pro UDMA7 150/150MBps),and the buffer was still full after 35frames continious shooting.

When I read about the 12fps performance of this camera I was excited – especially given the larger image size – but I was also worried as my 10fps performance of the 1D Mark III & IV has always been significantly limited by its puny buffer. In my early testing with what I was told was a slow CF card, I was able to get 52 full-size RAW frames in burst mode before the buffer started to stutter. That’s up from 30 in the 1D Mark IV, so that’s promising given the significantly larger file sizes. However, I would have really loved to have seen that number closer to 100 for RAW. RAM is pretty cheap, so I’m always frustrated there isn’t a way to add RAM or do something to overcome this limitation. With that gripe aside, the 52 RAW frames is going to be usable enough in most practical scenarios so this is a welcome relief. This also means that sRAW or JPEG only shooters will find themselves with an endless supply of buffer for sports shooting.

Indeed, and check Ole Salomonsen comments back then in that thread!!! (which he (Ron) called BS!! )

« Last Edit: June 12, 2012, 01:21:42 PM by messus »

Logged

canon rumors FORUM

IF, and I know it's a big "if," the 5D Mark III is anything to go by, it is worth noting that the a search of the Canonrumours historic posts reveals that the 5D Mark III owner's manual was posted approximately one week before vendors started shipping cameras that had been pre-ordered. (Followed by fits and starts of availability)

I realize that the 1DX has been a different beast, and that the availability in different countries may vary depending on whether Canon is adhereing to their "Olympic photographers first" philosophy in particular countries (earlier threads suggested that this was not going to happen in the U.S., even though it was in Canada), available only in limited quantities at first, your mileage may vary, blah, blah, blah.

That said, none of us can get one until they START SHIPPING, so maybe that trigger date is now within a week or two. I, for one, am happy to have something to look forward to.

Looking at page 393, it looks like the 1Dx is going to use the same codec as the 5d3(same data-rate), so I doubt their will be any improvement in the video. That's absurd for the amount of horsepower this thing has. Totally nerfed.

Still kinda an expensive camera to buy to rely on and wait for Magic Lantern (or others) to enable higher video bitrate, and clean HDMI out!

Canon need to understand it does not help if they cripple the 1DX for features to prevent canibalizing their video department, as long as the competition gives us the features (Nikon=clean HDMI out) there is always a risk of some users jumping ship.

Probably not going to happen for Magic Lantern. They tried to get it working for the 7d which has dual Digic processors which was a problem for them. They have it booted on the 5d3, although it's so far from even having an Alpha release it'll probably be a year unless they can get someone devoted full time to develop on it. If they can eventually figure out multiple Digic cameras, then it may be possible to come to the 1DX, but it probably won't happen.

You are probably right. And the more I think about it, I am considering canceling my 1DX preorder since it IMO is simply not worth it given too few extra benefits compared to the 5D3. (weather sealing put aside). No noticable improvement in high ISO performance, DR or picture quality from what I can see from my own testing. And, in particular due to the dissapointingly low buffer of the 1DX you will in many cases not be fully able to utilize the shutter speed improvements on the 1DX over the 5D3.

And if Canon think I am gonna ruin myself with 15000 dollars to get clean HDMI out from the 1D C, they have to think twice. I know of other ways of getting what I want, even if it is drastic and expensive, it may still be cheaper than spending 15000 on the 1D C.

Hey let's hope ML at least get's things going for clean HDMI out on the 5D3, and maybe even short bursts of 4K video.

If you mostly shoot video, why would you go for the 1DX to begin with? I'd think, at that level, you'd go for a more dedicated video option. I don't know prices exactly, but I've read that there are some reasonably priced (I think ~$10K or so) options for other manufacturers with similar or more features than the 1D C.

I don't really do much video, but I do have the 5d2 and I'd love to get a hold of ML (hopefully closed beta will be over soon) and play with it more. Things like the focus assist zebra striping, PiP 5x zoomed for precise focusing. And I hope they can get it on the 5d3 and do things like 1080@60p, maybe better/higher bit-rate/compression options, maybe even MJPEG? I wonder if the JPEG engine can keep with with 24/30/60 fps. That'd be freaking awesome, even if it's just 1080/720. Even better if we could get S1 (2880 x 1920) sized JPEGs. That'd seriously be awesome!

Excuse my ignorance but can someone explain in plain english why the camera can't focus at F8.0?I have a 24-70 2.8L and use F8 all the time... I find it to be the best, sharpest and most natural F-stop for studio work...Please someone tell me if that is going to affect me or not.

Cheers

Pat

All lenses focus at their maximum aperature. You're lens has a max of 2.8, therefore the autofocus will work splendidly. The camera doesn't close down the aperature until you hit the shutter button (or the dof preview). As long as you don't use teleconverters you should never run into a situation where AF does not work. I would venture to say if you don't know this stuff then you probably shouldn't be getting a 1DX anyway.

Excuse my ignorance but can someone explain in plain english why the camera can't focus at F8.0?I have a 24-70 2.8L and use F8 all the time... I find it to be the best, sharpest and most natural F-stop for studio work...Please someone tell me if that is going to affect me or not.

Cheers

Pat

All lenses focus at their maximum aperature. You're lens has a max of 2.8, therefore the autofocus will work splendidly. The camera doesn't close down the aperature until you hit the shutter button (or the dof preview). As long as you don't use teleconverters you should never run into a situation where AF does not work. I would venture to say if you don't know this stuff then you probably shouldn't be getting a 1DX anyway.

I don't think that knowledge excludes anyone from owning a 1DX or any body for that matter. The poster who asked this question is a pro and shoots very fine photographs. If you've never had to run into this situation, ie you don't use teleconverters, then it matters none that you wouldn't know this.

The one thing that dissapoints me with the 1DX is the buffer size and the number of RAW frames possible to store during a high burst.The 35 frames takes only 3seconds, 3 !!!!! to fill the buffer..

Anyway, there seem to be something strange going on, since shooting m-RAW mode actually decreases the number of possible burts shots to 26, while shooting s-RAW mode increases the number to 39. I understand it takes some computing time to resize the RAW, but this will also happen while downsizine to s-RAW. Hence it is strange that the number of frames possible during m-RAW is "only" 26,which is a ridicilously small number which you will reach within 1.5sec !! Why could not Canon install a 3 x bigger buffer when the restof the camera is built for speed?? (shutter/cpu). The D4 can shoot up to 3 times more frames than the 1DX.

I have tested the 1DX with the fastest memory card currently available on the planet (Lexar 128G 1000x Pro UDMA7 150/150MBps),and the buffer was still full after 35frames continious shooting.

When I read about the 12fps performance of this camera I was excited – especially given the larger image size – but I was also worried as my 10fps performance of the 1D Mark III & IV has always been significantly limited by its puny buffer. In my early testing with what I was told was a slow CF card, I was able to get 52 full-size RAW frames in burst mode before the buffer started to stutter. That’s up from 30 in the 1D Mark IV, so that’s promising given the significantly larger file sizes. However, I would have really loved to have seen that number closer to 100 for RAW. RAM is pretty cheap, so I’m always frustrated there isn’t a way to add RAM or do something to overcome this limitation. With that gripe aside, the 52 RAW frames is going to be usable enough in most practical scenarios so this is a welcome relief. This also means that sRAW or JPEG only shooters will find themselves with an endless supply of buffer for sports shooting.

Indeed, and check Ole Salomonsen comments back then in that thread!!! (which he (Ron) called BS!! )

I re-read those comments to get a refresh on that, but dug further to some reliable sources. When you tested the 1Dx, where and when did you get to test it?

Here's what I'm finding odd on your comments:

1) the 1Dx manual states in RAW the burst is 35 images with a regular card and 38 with a UDMA 7 card. If the data xfer rate of 167MB/sec (max) for UMDA7 is supported, as stated in the specifications for the 1Dx, then I would expect that Ron's numbers of approx 50-55 RAW images to be about right. Your statements would have you believe that zero data made it out of the Lexar UDMA7 card, something not possible.

2) I know from experience with my 5D3, I can shoot approx 19-20 RAW images at 6 fps on a SanDisk Extreme Pro 32GB UDMA6 card before the buffer stutters. The 5D3 manual states it's RAW burst is 13 images, 18 when using UDMA7. I have not used a UDMA7 card in the 5D3 yet but would expect a little better performance than I have observed.

3) The D4 numbers you claim are highly questionable given reliable testing. For example, they totally conflict with Rob Galbraith's documented testing. That testing shows in a 30 second period the D4 using a Lexar 1000x 32GB UDMA7 was able to write 86 RAW+Jpeg images, with a max RAW data rate of 61.4MB/s. In the same testing with the same card on the 5D3, it could write 75 RAW+Jpeg images with a max RAW data rate of 80.2MB/s .

So, given documented testing by a known method and source of information that is also well know for his like of Nikon, the 5D3 is out performing the RAW xfer rate of the D4 by about 19MB/sec on the same card. I seriously doubt the 1Dx would be slower than the 5D3. In combined RAW+Jpeg, the D4 manages just 11 images more than the 5D3 in 30 seconds of shooting despite the 5D3's RAW+L-Jpeg rated burst capacity of 7 images. And let's not forget the 5D3 is a 22Mpix image....the D4 is 16Mpix, about 30% smaller.

This does not agree with your claims of the 1Dx or the D4's image rates and burst capacity. The D4 is barely outperforming RAW+Jpeg compared to the 5D3. So, can you tell us when you tested the 1Dx, where and when did you get to test it with the Lexar 1000x card?

Further, if anyone is wondering why M-RAWand S-RAW numbers seem odd, it because M-RAW is a 10M image which requires more processing (size reduction to a non-multiple of the RAW and processing to handle that). S-RAW you will note is exactly 1/4 of the original RAW (4.5M vs. 18M), so the math is far simpler, thus the greater burst ability.

Excuse my ignorance but can someone explain in plain english why the camera can't focus at F8.0?I have a 24-70 2.8L and use F8 all the time... I find it to be the best, sharpest and most natural F-stop for studio work...Please someone tell me if that is going to affect me or not.

Cheers

Pat

All lenses focus at their maximum aperature. You're lens has a max of 2.8, therefore the autofocus will work splendidly. The camera doesn't close down the aperature until you hit the shutter button (or the dof preview). As long as you don't use teleconverters you should never run into a situation where AF does not work. I would venture to say if you don't know this stuff then you probably shouldn't be getting a 1DX anyway.

I've been shooting pro for 9 year but I never owned a 300mm or 400mm or any lens that needs a teleconverter.I only own ONE lens (24-70 F2.8L) and that is all I need. I don't do sports or birds or need telephoto lenses.I don't know about this F8.0 phenomenon because it has never been an issue for me.But I really don't like your comment. I can get any camera I want and it doesn't make me less of a Pro not knowing all this technical stuff... On the contrary, you are either creative or not. You are born with it. I never took classes or studied any photography and I make a ton of money doing what I love. If you had to learn it, then you didn't have it... I only use the things and features I need in a camera and I've been using 1D's since 2003 so the obvious upgrade from my current 1D IV is the 1D X...

Excuse my ignorance but can someone explain in plain english why the camera can't focus at F8.0?I have a 24-70 2.8L and use F8 all the time... I find it to be the best, sharpest and most natural F-stop for studio work...Please someone tell me if that is going to affect me or not.

Cheers

Pat

All lenses focus at their maximum aperature. You're lens has a max of 2.8, therefore the autofocus will work splendidly. The camera doesn't close down the aperature until you hit the shutter button (or the dof preview). As long as you don't use teleconverters you should never run into a situation where AF does not work. I would venture to say if you don't know this stuff then you probably shouldn't be getting a 1DX anyway.

I don't think that knowledge excludes anyone from owning a 1DX or any body for that matter. The poster who asked this question is a pro and shoots very fine photographs. If you've never had to run into this situation, ie you don't use teleconverters, then it matters none that you wouldn't know this.

Than for your comment. I am really disappointed at these forums. Mostly everybody is acting defensively or aggressively... You can't ask a valid question without getting a dumb answer in return. I am getting tired of this. We should all learn from each other... That's what this is about.

The one thing that dissapoints me with the 1DX is the buffer size and the number of RAW frames possible to store during a high burst.The 35 frames takes only 3seconds, 3 !!!!! to fill the buffer..

Anyway, there seem to be something strange going on, since shooting m-RAW mode actually decreases the number of possible burts shots to 26, while shooting s-RAW mode increases the number to 39. I understand it takes some computing time to resize the RAW, but this will also happen while downsizine to s-RAW. Hence it is strange that the number of frames possible during m-RAW is "only" 26,which is a ridicilously small number which you will reach within 1.5sec !! Why could not Canon install a 3 x bigger buffer when the restof the camera is built for speed?? (shutter/cpu). The D4 can shoot up to 3 times more frames than the 1DX.

I have tested the 1DX with the fastest memory card currently available on the planet (Lexar 128G 1000x Pro UDMA7 150/150MBps),and the buffer was still full after 35frames continious shooting.

When I read about the 12fps performance of this camera I was excited – especially given the larger image size – but I was also worried as my 10fps performance of the 1D Mark III & IV has always been significantly limited by its puny buffer. In my early testing with what I was told was a slow CF card, I was able to get 52 full-size RAW frames in burst mode before the buffer started to stutter. That’s up from 30 in the 1D Mark IV, so that’s promising given the significantly larger file sizes. However, I would have really loved to have seen that number closer to 100 for RAW. RAM is pretty cheap, so I’m always frustrated there isn’t a way to add RAM or do something to overcome this limitation. With that gripe aside, the 52 RAW frames is going to be usable enough in most practical scenarios so this is a welcome relief. This also means that sRAW or JPEG only shooters will find themselves with an endless supply of buffer for sports shooting.

Indeed, and check Ole Salomonsen comments back then in that thread!!! (which he (Ron) called BS!! )

I re-read those comments to get a refresh on that, but dug further to some reliable sources. When you tested the 1Dx, where and when did you get to test it?

Here's what I'm finding odd on your comments:

1) the 1Dx manual states in RAW the burst is 35 images with a regular card and 38 with a UDMA 7 card. If the data xfer rate of 167MB/sec (max) for UMDA7 is supported, as stated in the specifications for the 1Dx, then I would expect that Ron's numbers of approx 50-55 RAW images to be about right. Your statements would have you believe that zero data made it out of the Lexar UDMA7 card, something not possible.

2) I know from experience with my 5D3, I can shoot approx 19-20 RAW images at 6 fps on a SanDisk Extreme Pro 32GB UDMA6 card before the buffer stutters. The 5D3 manual states it's RAW burst is 13 images, 18 when using UDMA7. I have not used a UDMA7 card in the 5D3 yet but would expect a little better performance than I have observed.

3) The D4 numbers you claim are highly questionable given reliable testing. For example, they totally conflict with Rob Galbraith's documented testing. That testing shows in a 30 second period the D4 using a Lexar 1000x 32GB UDMA7 was able to write 86 RAW+Jpeg images, with a max RAW data rate of 61.4MB/s. In the same testing with the same card on the 5D3, it could write 75 RAW+Jpeg images with a max RAW data rate of 80.2MB/s .

So, given documented testing by a known method and source of information that is also well know for his like of Nikon, the 5D3 is out performing the RAW xfer rate of the D4 by about 19MB/sec on the same card. I seriously doubt the 1Dx would be slower than the 5D3. In combined RAW+Jpeg, the D4 manages just 11 images more than the 5D3 in 30 seconds of shooting despite the 5D3's RAW+L-Jpeg rated burst capacity of 7 images.

This does not agree with your claims of the 1Dx or the D4's image rates and burst capacity. The D4 is barely outperforming RAW+Jpeg compared to the 5D3. So, can you tell us when you tested the 1Dx, where and when did you get to test it with the Lexar 1000x card?

Further, if anyone is wondering why M-RAWand S-RAW numbers seem odd, it because M-RAW is a 10M image which requires more processing (size reduction to a non-multiple of the RAW and processing to handle that). S-RAW you will note is exactly 1/4 of the original RAW (4.5M vs. 18M), so the math is far simpler, thus the greater burst ability.

People will get excited about a 12fps camera like I got excited when I got my 1D IV. But the only way my camera can do 10fps is in one-shot focusing. Put the camera in AI servo and there is no way the camera will focus quickly enough to maintain 10fps... Specially if the subject is running towards you... Even with 10 processors, the AF system needs time to accurately focus. You can tell the camera to shoot anyway, but who cares for an out of focus image anyway...I hope the new AF system on the 1D X will be able to "keep up" with the camera's fps...

People will get excited about a 12fps camera like I got excited when I got my 1D IV. But the only way my camera can do 10fps is in one-shot focusing. Put the camera in AI servo and there is no way the camera will focus quickly enough to maintain 10fps... Specially if the subject is running towards you... Even with 10 processors, the AF system needs time to accurately focus. You can tell the camera to shoot anyway, but who cares for an out of focus image anyway...I hope the new AF system on the 1D X will be able to "keep up" with the camera's fps...[/quote]

Your observation got me interested in what kind of qualifications Canon put on its "12 frames per second" rating (something that I am looking forward to), so I looked it up in their new online manual, and here is what they say (assuming you can decipher it):

From p. 111 of the manual, "The maximum continuous shooting speed of approx. 12 shots/sec. is attained under the following conditions*: At ISO 25600 or lower, 1/1000 sec. or faster shutter speed, and at the maximum aperture (varies dependin on the lens). The continuous shooting speed may be slower depending on the ISO speed, shutter speed, aperture, subject conditions, brightness, lens type, flash use, etc. *With the AF mode set to One-shot AF and the Image Stabilizer turned off when using the following lenses: EF 300mm f/4L IS USM, EF28-135mm f3.5-5.6 IS USM, EF 75-300mm f/2-5.6 IS USM, EF 100-400mm f/4.5-5.6L IS USM."

More disclaimers than the end of a used car dealership commercial! Can anyone say whether the asterisked text at the end is intended to mean that you only get 12 fps in one shot AF mode AND with those lenses, or whether instead they are saying that those lenses are a special case, and for them you have to use one-shot AF and turn off image stabilization?

MarkWebbPhoto

Jax, those lenses are extremely slow. They will most definitely shoot at a slower speed since the AF will take longer to lock on. And while I know my 1D MK IV never really gets 10 FPS unless I hit have the camera in one shot, I can use the AF stop button on my super-telephoto lenses to get the max burst speed. This works great for baseball if you want a shot of the ball leaving the bat. 12 FPS just means that I should get at least 10 in AI-Servo. I also noticed a frame rate increase when I updated my 70-200 f/2.8L IS to the newest version. The 70-200 f/2.8 IS II seems to give me an even faster frame rate than my 300 f/2.8 IS or 200 f/2.0 IS but maybe that is just me.

The buffer should hold around 50 RAW images, the 30 image buffer must have been an early model. Keep in mind we are still dealing with pre-production bodies. Lord knows what is inside those.

People are still comparing the 5D MK III to the 1DX, they are completely different monsters. In my testing I saw only a little more than 1 stop improvement in high ISO with the 5D3 over the 5D2. I've downloaded and played with several 1DX files and they look absolutely phenomenal. The 1DX probably has at least a 3-stop advantage over the 5D2.

This is a great year for Canon and I'm excited to finally get a camera body that combines my favorite features of the full frame bodies with the pro sports bodies. At one point I almost switched to Nikon but this is truly the year the be a Canon shooter. I'm already in love with the radio capabilities of the 600EX-RT.

canon rumors FORUM

Video file attached shows buffer of 1D X stop after 36 frames using the fastest memory card on the planet as of today. I had to downsize the video file to 480x270 mpeg2 and compress it heavily to be allowed to upload it here with the file size limit of 4096KB. The Lexar Pro UDMA7 card is mine, I am using it on my 5D3. I brought the card with me to a photography show here in Norway where they had the 1DX. I put my Lexar UDMA7 Pro card into the 1DX and my friend filmed while I kept the trigger until the buffer was full.

The one thing that dissapoints me with the 1DX is the buffer size and the number of RAW frames possible to store during a high burst.The 35 frames takes only 3seconds, 3 !!!!! to fill the buffer..

Anyway, there seem to be something strange going on, since shooting m-RAW mode actually decreases the number of possible burts shots to 26, while shooting s-RAW mode increases the number to 39. I understand it takes some computing time to resize the RAW, but this will also happen while downsizine to s-RAW. Hence it is strange that the number of frames possible during m-RAW is "only" 26,which is a ridicilously small number which you will reach within 1.5sec !! Why could not Canon install a 3 x bigger buffer when the restof the camera is built for speed?? (shutter/cpu). The D4 can shoot up to 3 times more frames than the 1DX.

I have tested the 1DX with the fastest memory card currently available on the planet (Lexar 128G 1000x Pro UDMA7 150/150MBps),and the buffer was still full after 35frames continious shooting.

When I read about the 12fps performance of this camera I was excited – especially given the larger image size – but I was also worried as my 10fps performance of the 1D Mark III & IV has always been significantly limited by its puny buffer. In my early testing with what I was told was a slow CF card, I was able to get 52 full-size RAW frames in burst mode before the buffer started to stutter. That’s up from 30 in the 1D Mark IV, so that’s promising given the significantly larger file sizes. However, I would have really loved to have seen that number closer to 100 for RAW. RAM is pretty cheap, so I’m always frustrated there isn’t a way to add RAM or do something to overcome this limitation. With that gripe aside, the 52 RAW frames is going to be usable enough in most practical scenarios so this is a welcome relief. This also means that sRAW or JPEG only shooters will find themselves with an endless supply of buffer for sports shooting.

Indeed, and check Ole Salomonsen comments back then in that thread!!! (which he (Ron) called BS!! )

I re-read those comments to get a refresh on that, but dug further to some reliable sources. When you tested the 1Dx, where and when did you get to test it?

Here's what I'm finding odd on your comments:

1) the 1Dx manual states in RAW the burst is 35 images with a regular card and 38 with a UDMA 7 card. If the data xfer rate of 167MB/sec (max) for UMDA7 is supported, as stated in the specifications for the 1Dx, then I would expect that Ron's numbers of approx 50-55 RAW images to be about right. Your statements would have you believe that zero data made it out of the Lexar UDMA7 card, something not possible.

2) I know from experience with my 5D3, I can shoot approx 19-20 RAW images at 6 fps on a SanDisk Extreme Pro 32GB UDMA6 card before the buffer stutters. The 5D3 manual states it's RAW burst is 13 images, 18 when using UDMA7. I have not used a UDMA7 card in the 5D3 yet but would expect a little better performance than I have observed.

3) The D4 numbers you claim are highly questionable given reliable testing. For example, they totally conflict with Rob Galbraith's documented testing. That testing shows in a 30 second period the D4 using a Lexar 1000x 32GB UDMA7 was able to write 86 RAW+Jpeg images, with a max RAW data rate of 61.4MB/s. In the same testing with the same card on the 5D3, it could write 75 RAW+Jpeg images with a max RAW data rate of 80.2MB/s .

So, given documented testing by a known method and source of information that is also well know for his like of Nikon, the 5D3 is out performing the RAW xfer rate of the D4 by about 19MB/sec on the same card. I seriously doubt the 1Dx would be slower than the 5D3. In combined RAW+Jpeg, the D4 manages just 11 images more than the 5D3 in 30 seconds of shooting despite the 5D3's RAW+L-Jpeg rated burst capacity of 7 images. And let's not forget the 5D3 is a 22Mpix image....the D4 is 16Mpix, about 30% smaller.

This does not agree with your claims of the 1Dx or the D4's image rates and burst capacity. The D4 is barely outperforming RAW+Jpeg compared to the 5D3. So, can you tell us when you tested the 1Dx, where and when did you get to test it with the Lexar 1000x card?

Further, if anyone is wondering why M-RAWand S-RAW numbers seem odd, it because M-RAW is a 10M image which requires more processing (size reduction to a non-multiple of the RAW and processing to handle that). S-RAW you will note is exactly 1/4 of the original RAW (4.5M vs. 18M), so the math is far simpler, thus the greater burst ability.

1) Ron's numbers are wrong, sadly, check my proof video I posted in this thread. I have used the fastest memory card available, Lexar 128GB CF UDMA7 Pro, which I use daily with my 5D3. The 5D3 Canon also claim to be able to fully utilize any UDMA7 card with up to 167MB/s, which I have found to be wrong.The 5D3 is capable of almost 100MB/s, about the same as the D4. (tested with speeds which allowed for continous shooting without the buffer stopping)

2) I am capable of shooting 33-34 RAW images at 6fps on my 5D3 with the Lexar UDMA7 card before buffer stops.

3) Seem like I am not entirely correct on the D4, (although I have read several places it could go higher), this guy is achieving 6-7 seconds continous shooting until buffer is full (at 05:45), this should mean 60-70 RAW files:XQD + Nikon D4 full speed test

I have also done extensive speed testing on my own with the 5D3, 5D2, the D4, D800 and D800E, all with the Lexar 128GB UDMA7 CF Pro 1000x, since I work a lot with stop motion video in the dark, and need the cameras to be able to shoot as fast as possible without the buffer stopping. The 5D3 has about the same write speed as the D4. IMO the D4 is actually slightly disappointing in its computing power, taking into account its fast shutter mechanics. Still its buffer seem to be larger than the 1DX, since RAW files of D4 is actually 33MB compared to 28 on the 1DX.

With the price tag, and the shutter speed and the computing power availbale on the 1DX, I have to say I it is disappointing Canon did not implement a bigger buffer, given also how cheap flash ram is these days, even if it might be enough for many people.

For my type of work, I am guessing the 1DX will still outperform the D4 (shooting as fast as possible without the buffer interfering), but thats not the only point. Even if my type of work is not what most people do, I also do regular work, such as wildlife and bird photography (BIF), and what If I am shooting an eagle diving down for a fish? This is a moment which could take much more than 3 seconds, sometimes 7-8seconds. But then the buffer on the 1DX is full..

And if I have to turn down the shooting speed of the 1DX to not fill up the buffer, then what is the point of me spending 7000 dollars on the 1DX rather than just using my 5D3 ?